calabar bean

from WordNet (r) 3.0 (2006)

calabar bean
    n 1: dark brown highly poisonous seed of the calabar-bean vine;
         source of physostigmine and used in native witchcraft [syn:
         {calabar bean}, {ordeal bean}]

from The Collaborative International Dictionary of English v.0.48

Calabar \Cal"a*bar\, n.
   A district on the west coast of Africa.
   [1913 Webster]

   {Calabar bean}, The of a climbing legumious plant
      ({Physostigma venenosum}), a native of tropical Africa. It
      is highly poisonous. It is used to produce contraction of
      the pupil of the eye; also in tetanus, neuralgia, and
      rheumatic diseases; -- called also {ordeal bean}, being
      used by the negroes in trials for witchcraft.
      [1913 Webster]